Burn-in Procedure Based on a Dependent Covariate Process

Burn-in is a method of ‘elimination’ of initial failures (infant mortality). In the conventional burn-in procedures, to burn-in a component or a system means to subject it to a fixed time period of simulated use prior to actual operation. Then those which fail during the burn-in procedure are scrapped and only those which survived the burn-in procedure are considered to be of satisfactory quality. Thus, in this case, the only information used for the elimination procedure is the lifetime of the corresponding item. In this paper we consider a new burn-in procedure which additionally employs a dependent covariate process in the elimination procedure. Through the comparison with the conventional burn-in procedure, we show that the new burn-in procedure is preferable under commonly satisfied conditions. The problem of determining the optimal burn-in parameters is also considered and the properties of the optimal parameters are derived. A numerical example is provided to illustrate the theoretical results obtained in this paper.

Download Full-text

Stability of Delayed Hopfield Neural Networks with Variable-Time Impulses

Mathematical Problems in Engineering ◽

10.1155/2014/154036 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Yangjun Pei ◽

Chao Liu ◽

Qi Han

Keyword(s):

Neural Networks ◽

Exponential Stability ◽

Fixed Time ◽

Hopfield Neural Networks ◽

Stability Criteria ◽

Variable Time ◽

Numerical Example ◽

Globally Exponential Stability ◽

Theoretical Results

In this paper the globally exponential stability criteria of delayed Hopfield neural networks with variable-time impulses are established. The proposed criteria can also be applied in Hopfield neural networks with fixed-time impulses. A numerical example is presented to illustrate the effectiveness of our theoretical results.

Download Full-text

Utilization of remote sensing for estimation of scale of cutting and growing of forest zones

Geodesy and Cartography ◽

10.22389/0016-7126-2017-920-2-57-60 ◽

2017 ◽

Vol 920 (2) ◽

pp. 57-60

Author(s):

F.E. Guliyeva

Keyword(s):

Remote Sensing ◽

Fixed Time ◽

Time Interval ◽

Time Points ◽

Average Value ◽

Time Period ◽

Remote Estimation ◽

The Given ◽

Forest Cutting

The study of results of relevant works on remote sensing of forests has shown that the known methods of remote estimation of forest cuts and growth don’t allow to calculate the objective average value of forests cut volume during the fixed time period. The existing mathematical estimates are not monotonous and make it possible to estimate primitively the scale of cutting by computing the ratio of data in two fixed time points. In the article the extreme properties of the considered estimates for deforestation and reforestation models are researched. The extreme features of integrated averaged values of given estimates upon limitations applied on variables, characterizing the deforestation and reforestation processes are studied. The integrated parameter, making it possible to calculate the averaged value of estimates of forest cutting, computed for all fixed time period with a fixed step is suggested. It is shown mathematically that the given estimate has a monotonous feature in regard of value of given time interval and make it possible to evaluate objectively the scales of forest cutting.

Download Full-text

A Method for Evaluating the Thermal Performance of Passenger Seats

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1243/095440703766518087 ◽

2003 ◽

Vol 217 (6) ◽

pp. 449-459 ◽

Cited By ~ 2

Author(s):

E B Ratts ◽

J W McElroy ◽

W G Reed

Keyword(s):

Thermal Performance ◽

Thermal Energy ◽

Water Source ◽

Fixed Time ◽

Test Method ◽

Test Apparatus ◽

Passenger Seat ◽

Time Period ◽

Seat Cushion ◽

Heat And Moisture

In this paper, an experimental method to quantify the capability of an automotive seat to move heat and moisture away from the heat and water source is presented. To test the method, a test apparatus was constructed that generates heat and water vapour. The apparatus was placed on a seat cushion for a fixed time period. At the end of the period, heat and water transported were measured. These integrated values were used to quantify the seat's capability to move heat and moisture and ultimately to compare seats. By the impulse test method, the passenger seat had an effusivity of 94.7 W s1/2/m2 K. A non-ventilated seat transferred 5 W of thermal energy and an average of 0.36 g/min of water in 1800 s. A ventilated seat transferred 13.9 W of thermal energy and 0.70 g/min of water in 1800 s.

Download Full-text

Self-Controlled Practice Within a Fixed Time Period Facilitates the Learning of a Basketball Set Shot

Journal of Motor Learning and Development ◽

10.1123/jmld.2013-0008 ◽

2014 ◽

Vol 2 (1) ◽

pp. 9-15 ◽

Cited By ~ 23

Author(s):

Phillip G. Post ◽

Jeffrey T. Fairbrother ◽

Joao A. C. Barros ◽

J. D. Kulpa

Keyword(s):

Motor Learning ◽

Instructional Support ◽

Fixed Time ◽

Relevant Information ◽

Self Control ◽

Time Period ◽

Trial Basis ◽

Practice Trials ◽

Additional Support ◽

Do So

Allowing self-control over various modes of instructional support has been shown to facilitate motor learning. Most research has examined factors that directly altered task-relevant information on a trial-to-trial basis (e.g., feedback). Recent research suggests that self-control (SC) effects extend to the manipulation of other types of factors (e.g., total number of practice trials completed). This research also illustrated that learners sometimes select a very small amount of practice when given latitude to do so. The purpose of the current study was to examine the effects of SC practice within a fixed time period on the learning of a basketball set shot. SC participants chose when to attempt each shot within two 15-min practice sessions, thereby controlling both the total number of shots taken and the spacing of shots. Yoked participants completed the same number of shots as their SC counterparts. Spacing of shots was also matched across groups. The SC group was more accurate and had higher form scores and longer preshot times during retention. These findings provided additional support for the generalizability of SC effects and extended prior research, showing that autonomy over total practice duration was not a prerequisite for the observed effects.

Download Full-text

Mixture copulas and insurance applications

Annals of Actuarial Science ◽

10.1017/s174849951800012x ◽

2018 ◽

Vol 12 (2) ◽

pp. 391-411

Author(s):

Maissa Tamraz

Keyword(s):

Joint Distribution ◽

Stable Distribution ◽

Random Variable ◽

Fixed Time ◽

Collective Model ◽

Data Sets ◽

New Model ◽

Time Period ◽

Insurance Data ◽

Dependence Property

AbstractIn the classical collective model over a fixed time period of two insurance portfolios, we are interested, in this contribution, in the models that relate to the joint distributionFof the largest claim amounts observed in both insurance portfolios. Specifically, we consider the tractable model where the claim counting random variableNfollows a discrete-stable distribution with parameters (α,λ). We investigate the dependence property ofFwith respect to both parametersαandλ. Furthermore, we present several applications of the new model to concrete insurance data sets and assess the fit of our new model with respect to other models already considered in some recent contributions. We can see that our model performs well with respect to most data sets.

Download Full-text

Two-Step Solver for Nonlinear Equations

Symmetry ◽

10.3390/sym11020128 ◽

2019 ◽

Vol 11 (2) ◽

pp. 128 ◽

Cited By ~ 4

Author(s):

Ioannis Argyros ◽

Stepan Shakhno ◽

Halyna Yarmola

Keyword(s):

Nonlinear Equations ◽

Order Of Convergence ◽

Semilocal Convergence ◽

Numerical Example ◽

Weaker Conditions ◽

Theoretical Results ◽

Nondifferentiable Operator

In this paper we present a two-step solver for nonlinear equations with a nondifferentiable operator. This method is based on two methods of order of convergence 1 + 2 . We study the local and a semilocal convergence using weaker conditions in order to extend the applicability of the solver. Finally, we present the numerical example that confirms the theoretical results.

Download Full-text

Traffic Management Parameters from Single Inductive Loop Detectors

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1719-14 ◽

2000 ◽

Vol 1719 (1) ◽

pp. 112-120 ◽

Cited By ~ 13

Author(s):

Tom Cherrett ◽

Hugh Bell ◽

Mike McDonald

Keyword(s):

Traffic Control ◽

Traffic Management ◽

Fixed Time ◽

Urban Traffic ◽

Flow Conditions ◽

Inductive Loop ◽

Loop Detectors ◽

Time Period ◽

S Period ◽

Urban Traffic Control

Investigated are potential new uses for the digital output produced by single inductive loop detectors (2 m x 1.5 m and 2 m x 6.5 m) used in most European urban traffic control systems. Over a fixed time period, the average loop-occupancy time per vehicle (ALOTPV) for a detector being sampled every 250 ms is determined by taking the number of 250-ms occupancies and dividing by the number of vehicles. In a similar way, the average headway time between vehicles (AHTBV) is determined by taking the number of 250-ms vacancies and dividing by the number of vehicles. Over a 30-s period, the minimum and maximum values of ALOTPV and AHTBV ranged from 1 to 120 (an ALOTPV of 1 and an AHTBV of 120 representing free-flow conditions, an ALOTPV of 120 and an AHTBV of 1 representing a stationary queue). Identifying periods when a link was operating under capacity and at capacity and when it had become saturated could be more clearly identified by using plots of ALOTPV and AHTBV data over time compared to the more traditional percentage occupancy output. ALOTPV also was used to successfully identify long vehicles from cars down to speeds of 15 km/h.

Download Full-text